Fix file missed from previous commit
Temporary alteration to save units in a dir named for their parent
Merge branch 'master' into tree_validation2
Extend validators to allow validating entire bundle tree. Eventually
all the validation functionality currently in the DAO should be put
here, including handling index collisions and generating indexes, but
this will follow.
Make the CSV importer not barf at the first invalid entry, and handle validator errors better.